Three delivery service partners said an Amazon.com app used to communicate with delivery drivers is down. Vans that were supposed to be on the road delivering packages are sitting idle with no communication from the company, the person said. Amazon Flex drivers, independent delivery people who carry parcels in their own cars, can’t log into Amazon’s app to get assignments, said another person.

The problems come amid Amazon’s critical holiday shopping season when the company can ill afford delays that could potentially create lasting logjams. One delivery business owner on the West Coast said the company halted deliveries on Tuesday and planned to regroup on Wednesday. 

Two delivery partners in earlier time zones said drivers that already had routes were instructed to put their phones in airplane mode and not log out of the Amazon routing app so they could continue making stops, but drivers who hadn’t already been assigned routes were sidelined.

“We are actively working on a number of different mitigation and resolution actions,” Amazon said on its AWS dashboard. “While we have observed some early signs of recovery, we do not have an ETA for full recovery.” The company didn’t immediately comment on the issues with its delivery operation.

The outage began at about 10 a.m. eastern time, according to DownDetector. At the height of the outage, the web monitoring site reported more than 20,000 complaints for Amazon and more than 11,000 for the company’s cloud computing arm, Amazon Web Services. By 1:45 p.m., the reported outages had declined by about half for AWS and two-thirds for Amazon.

Multiple popular websites were also affected, including those operated by Coinbase, Robinhood, Disney and Netflix, according to DownDetector. Disney said that though people were able to get into the parks, they were having difficulty checking in online and paying for purchases. Webcast presentations from Comcast and Altice USA. at UBS’s Global TMT Conference experienced disruptions earlier Tuesday, and the Charter Communications presentation was rescheduled for Wednesday.

Some Amazon services, including music and video streaming, the voice-activated Alexa platform and security arm, Ring, were affected, too.

AWS said it had identified the cause of “increased error rates” and is working to fix it. Meanwhile, the company is directing customers to alternative servers in its western region that aren’t experiencing problems. The increased errors are in the eastern North American region. Multiple Amazon cloud-computing services were affected, including Amazon DynamoDB and Amazon Elastic Compute.

Video streaming service Netflix experienced a 26% drop in traffic after the AWS problems were reported, showing how quickly outages can ripple outward, said Doug Madory, an analyst at the network monitoring firm Kentik in San Francisco.“ It gets more and more complicated with software running these services, so when something goes sideways it can take a long time to figure out what went wrong and fix it,” he said. “Complexity has risks. You introduce unknown errors.”

AWS is the leading cloud-computing provider, selling companies  computing power and software services on demand rather than maintaining their own data centers and teams in-house. Its customers include a wide range of industries and the federal government.